Genetic variation of Brucella isolates at strain level in Egypt

Abstract

In this study, Multiple Locus Variable Number Tandem Repeat Analysis (MLVA‐16) was performed on 18 Brucella isolates identified bacteriologically and molecularly (AMOS‐PCR) as Brucella abortus ( n = 6) and Brucella melitensis ( n = 12). This was aimed to study the genetic association among some Egyptian Brucella genotypes isolated during the period from 2002 to 2013 along with the global genotypes database. MLVA‐16 analysis for B. melitensis and B. abortus strains illustrates a total of 11, and 3 genotypes with 10 and 1 singleton genotypes, respectively. B. melitensis strains displayed greater markers diversity by VNTRs analysis of the 16 loci than B. abortus and this was attributed mainly to the diverging in panel 2B markers. B. melitensis genotype M4_Fayoum_Giza (3,5,3,13,1,1,3,3,8,21,8,7,5,9,5,3) was the only predominated genotype circulating between two different governorates. The most common B. abortus genotype, GT A3_Dakahlia (4,5,4,12,2,2,3,3,6,21,8,4,4,3,4,4), was present in three identical isolates. In phylogeny, Egyptian B. abortus bv1 genotypes were closely related to East Asian strain (for the first time), Western Mediterranean and Americas clonal lineages. B. melitensis local genotypes exhibit a genetic relatedness mostly to Western Mediterranean clonal lineage and one strain of Eastern Mediterranean clonal lineage. In conclusion, the geographic location is not the only factor stands behind the high genetic similarity of the Egyptian Brucella genotypes. These low variations may be a result of a stepwise mutational event of the most variable loci from a very limited number of ancestors especially during the transmission through non‐preference hosts. The authors encourage the authorities in charge to establish pre‐movement testing to reduce the risk of brucellosis spread.

Risk factors and Molecular genotyping of Brucella melitensis strains recovered from humans and their owned cattle in Upper Egypt

“…These results highlight the high degree of similarity of detected isolates that may indicate the circulation of the same or closely related strains of B. melitensis bv3 in the study region. Similarly, previous studies from Egypt showed high genetic similarity between B. melitensis bv3 isolates in several governorates [ 9 , 14 ]. This similarity of B. melitensis genotypes between different districts in Fayoum governorate may be attributed to free movement of animals between different districts.…”

“…In agreement, Brucella was isolated from 7.9% of human cases in Yemen [ 5 ]. The B. melitensis bv 3 is the most predominate species in Egypt [ 13 , 14 ] and the Middle East [ 3 ]. It is also the species most often isolated from cows in Egypt [ 9 , 13 ].…”

“…Three zoonotic Brucella species have been reported in Egypt: B. melitensis , B. abortus , and B. suis . The B. melitensis is the predominant species in livestock and humans [ 9 , 13 , 14 ]. The annual incidence of human brucellosis in the country is between 0.5/100,000 and 70/100,000, depending on the region of study [ [15] , [16] , [17] ].…”

MLVA-16 Genotyping of Brucella abortus and Brucella melitensis Isolates from Different Animal Species in Egypt: Geographical Relatedness and the Mediterranean Lineage

“…The strains revealed eleven and three genotypes, respectively. Brucella abortus isolates were closely related to Western, Mediterranean, and East Asian strains and clonal lineages from the Americas, and B. melitensis isolates were mostly closer to Western and Eastern Mediterranean clonal lineages [27]. A comprehensive genotyping of 118 Egyptian B. melitensis bv3 utilizing MLVA-16 showed correlation to the West Mediterranean lineage.…”

Validation of real-time polymerase chain reaction versus conventional polymerase chain reaction for diagnosis of brucellosis in cattle sera

“…At present, 11 species have been identified [1]. Among them, three species have been reported in Egypt; Brucella melitensis isolated from ruminants, Nile catfish, and humans; Brucella abortus isolated from cattle, dogs, and cats; and Brucella suis has been recovered from cattle and swine [2][3][4]. The identification of the Brucellae is done through the direct detection of Brucella organisms in milk, aborted material, lymph nodes, and other tissues through the isolation and typing of the causative microorganism or indirectly using serological tests.…”